1. Field of the Invention
The present invention relates to a method of forming an electrode on a ceramic green sheet and a method of manufacturing a multilayer ceramic electronic component, and more particularly, it relates to a method of forming an electrode such as a via hole electrode or a through hole electrode passing through a ceramic layer, and a method of manufacturing a multilayer ceramic electronic component having such a through electrode.
2. Description of the Background Art
A multilayer ceramic electronic component or a ceramic multilayer substrate having electronic component elements in its interior is provided with via hole electrodes or through hole electrodes passing through ceramic layers for connecting electrodes which are formed at different vertical positions in a ceramic sintered body FIG. 1 shows an exemplary multilayer ceramic electronic component 1 having such through electrodes.
The multilayer ceramic electronic component 1 shown in FIG. 1 has a sintered body 2 which is prepared by stacking a plurality of ceramic green sheets with each other and firing the obtained laminate. In this sintered body 2, internal electrodes 3 to 6 are formed at different vertical positions. The internal electrodes 3 and 4 are electrically connected with each other by a via hole electrode 7, while the internal electrodes 5 and 6 are also electrically connected with each other by another via hole electrode 8. External electrodes 9 and 10 are formed on both end surfaces of the sintered body 2 respectively.
In order to obtain the ceramic sintered body 2, in general, ceramic green sheets which are provided with the internal electrodes 3 to 6 on single major surfaces thereof respectively and blank ceramic sheets are stacked with each other to obtain a laminate. The ceramic green sheet which is provided with the internal electrode 3 on its upper surface is formed with a through hole, and this through hole is filled up with a conductive material to form the aforementioned via hole electrode 7. Similarly, the ceramic green sheet which is provided with the internal electrode 5 on its upper surface is formed with a through hole, and this through hole is filled up with a conductive material to form the via hole electrode 8.
The laminate obtained in the aforementioned manner is pressurized along its thickness, and thereafter fired at a prescribed temperature, to obtain the sintered body 2.
The ceramic green sheet for forming the via hole electrode 7 is prepared by the following method (see FIG. 2: First, a ceramic green sheet 12 is formed on a support film 11 consisting of synthetic resin such as polyethylene terephthalate by a doctor blade coater, for example, as shown in FIG. 2. Then, the ceramic green sheet 12 is punched with the support film 11, so that through holes 11a and 12a are formed therein. Thereafter the through holes 11a and 12a are filled up with conductive paste 13, and another conductive paste layer 14 is printed to define the internal electrode 3. In order to obtain the laminate, the ceramic green sheet 12 is separated from the support film 11, to be stacked with other ceramic green sheets.
In the conventional method, as hereinabove described, each of the via hole electrodes 7 and 8 must be formed through the complicated steps described with reference to FIG. 2. In other words, it is necessary to form a ceramic green sheet on a carrier film, then correctly form a through hole in a position for forming a via hole electrode, and thereafter fill up the through hole with a conductive material through complicated operations.